If you have asthma, your doctor may prescribe a nebulizer as treatment or breathing therapy. The device delivers the same types of medication as metered-dose inhalers (MDIs), which are the familiar pocket-sized inhalers. Nebulizers may be easier to use than MDIs, especially for children who aren’t old enough to properly use inhalers, or adults with severe asthma. A nebulizer turns liquid medicine into a mist to help treat your asthma. They come in electric or battery-run versions. They come in both a portable size you can carry with you and a larger size that’s meant to sit on a table and plug into a wall. Both are made up of a base that holds an air compressor, a small container for liquid medicine, and a tube that connects the air compressor to the medicine container. Above the medicine container is a mouthpiece or mask you used to inhale the mist. Pressurized air passes through the tube and turns the liquid medicine into a mist. During an asthma attack or a respiratory infection, the mist may be easier to inhale than the spray from a pocket inhaler. When your airways become narrow like during an asthma attack, you can’t take deep breaths. For this reason, a nebulizer is a more effective way to deliver the medication than an inhaler, which requires you to take a deep breath.